From late spring when the first sweet strawberries come into season through fall when juicy, tart apples are harvested, our local Virginia gardens are blessed with an abundance of fresh fruits. That’s the good news. The not-so-good news is that many of the fruits we grow are highly perishable. They must either be consumed right away or quickly preserved before they lose flavor or spoil. Depending on how much time and effort it will take to preserve the bounty, freezing may be your best option.
Why freeze fruit?
A key reason for freezing fruit is that it’s convenient to freeze now and then use the frozen product in recipes, like jams and jellies or desserts, later at your leisure. Freezing fruit is quick, simple to do, and requires no special supplies or equipment (other than a freezer). Unlike vegetables, which generally must be blanched (partially cooked) in hot water or steamed before freezing, fruits are usually frozen in their raw form.
Besides the convenience freezing offers, other reasons to freeze fruit are to:
- Preserve flavor. Fruits that are suitable for freezing should have a firm texture and well-developed flavor. In other words, they should be mature (well ripened). Freezing them as soon as possible after harvest preserves them at their peak of flavor.
- Preserve nutritional value. According to the Clemson Cooperative Extension’s factsheet HGIC 3063 on Freezing Fruits and Vegetables, freezing is “the method of food preservation that preserves the greatest quantity of nutrients.”
- Avoid food waste. Freezing extends the “shelf life” of fruits so that they can be used safely in a variety of ways later on. Keep in mind that freezing does not sterilize foods, but it does retard the growth of microorganisms and slows down the chemical changes that cause food to spoil.
How do you prevent frozen fruits from darkening or turning brown?
Some fruits that are sliced for freezing, notably tree fruits such as apples, peaches, pears, and nectarines, darken or turn brown when the cut surfaces are exposed to air. Unless the fruit is treated to prevent discoloration, darkening may start to happen as the fruit is being prepared for freezing and becomes apparent as the fruit is thawing.
While sugar helps prevent fruit from darkening, an additional application of an anti-browning agent such as lemon juice or ascorbic acid (vitamin C) is also helpful. Ascorbic acid not only preserves the natural color of the fruit and its flavor but also adds nutritional value. It is readily available at most grocery stores or where canning supplies are sold. To learn more, see the North Carolina State Extension’s publication on Brief Instructions for Freezing Fruit, which lists a variety of fruits and provides advice on how much ascorbic acid to use depending on how the fruit will be used.
What kind of containers should be used for freezing fruit?
To maintain maximum flavor, color, nutrients, and moisture content of fruits, it matters what kind of containers are used to freeze them. For fruits packed in syrup, juice, or other liquid, use rigid plastic containers or glass jars that are made for freezing and canning. Regular glass jars may break in freezing temperatures. For dry packed fruits with little or no liquid, plastic freezer-grade baggies work well. Leave a little head space for expansion but press the air out of the bag before sealing it.
What are some ways to pack fruits for freezing?
Most fruits yield better results if packed in sugar or syrup, which preserve flavor and texture. Other fruits can be packed for freezing without sugar or syrup.
- Syrup Pack: The syrup coats cut fruit and protects it from enzyme action that changes the fruit’s color and appearance. To make syrup, dissolve sugar in water and mix until the solution is clear. The ratio of sugar to water depends on the sweetness of the fruit. Light syrup is generally desirable for mild-tasting fruits to prevent overpowering the taste of the fruit. A heavier syrup may be preferable for very tart or sour fruits. As a general rule of thumb, a 40-percent syrup works for most fruits. Chill the syrup before using it. Pour just enough syrup in the container to cover the fruit.
- Dry Pack: Plain, dry sugar works well for fruits that produce juice, such as strawberries or peaches. Simply sprinkle the sugar over the fruit and gently combine it until the fruit pieces are covered in sugar and juice.
- Unsweetened: Small berries such as cranberries, blueberries, raspberries, blackberries and currants may be frozen without sugar. For small fruits such as these, the best way to freeze them is to spread them in a single layer on a tray small enough to fit in your freezer. Make sure they are not touching one another. The goal is to freeze the fruits individually so that they don’t clump together. Freeze the fruit only for as long as it takes to freeze solid. At that point, transfer it to freezer-proof containers and return it to the freezer. This technique allows you to remove as much of the frozen fruit as you want and return the unused portion to the freezer.
If you have a vacuum sealer, there’s no need to add juice or sugar syrup. Simply treat fruits with fruit preservative to prevent browning. Freeze the individual fruit pieces on a tray, then place them in freezer bags and vacuum seal them.
Can I use a sugar substitute instead of sugar to freeze fruit?
Although sweeteners such as aspartame may be used as a substitute for sugar, the results will not be the same. The fruit may freeze harder and thaw more slowly than those frozen using a dry sugar pack. Sugar substitutes also don’t typically keep fruit from darkening. Depending on your plans for the fruit, it may be preferable to freeze it unsweetened, then add the sugar substitute later when the fruit is ready to be served.
So, what are the steps for freezing fruits?
First, decide how you want to use the fruits after they are frozen. Will they be used whole, cut into chunks, sliced, crushed, pureed, or juiced? Your intended use of the fruits will determine how you prepare them for freezing.
The following are basics steps for freezing fruit:
- For best results, choose high quality fruits that are fully ripe. If the fruit has any damaged areas, cut those out.
- Place the fruits in a strainer or wire basket and rinse in cold water to remove any dirt or other debris. Drain thoroughly. Don’t let the fruits soak in the water. To prevent bruising the fruit, it’s best to wash small quantities at a time.
- Prepare the fruits using one of the methods described above (sugar syrup, dry sugar, or no sugar) as recommended for the fruit being frozen. If the fruit tends to turn brown, treat it with ascorbic acid or other anti-browning methods.
- Measure out the amount of fruit needed for a recipe. For example, it typically takes about four cups of sliced peaches to make a peach pie. Measure out that quantity for packing.
- Pack into freeze-proof plastic bags or other freezer-proof containers. Allow ½ inch of headspace for expansion. For fruits that tend to darken, keep them under the syrup by crumpling wax paper and placing it between the submerged fruit and the container lid.
How long can fruits be kept frozen?
According to the National Center for Home Food Preservation, most frozen fruits maintain their high quality for 8 to 12 months when stored at 0° F or lower. If stored longer than that, the quality of the fruits will decrease. Unsweetened fruits tend to lose quality faster than fruits packed in sugar or syrup.
What are some guidelines for thawing frozen fruits?
Fruits that are packed in dry sugar generally thaw faster than those packed in syrup. Fruits that are packed without sugar will generally take longer to thaw. Regardless of how the fruit was packed, always thaw it in the unopened container. Otherwise, the fruit may soften (or collapse) and darken in color if exposed to air while it is being thawed.
How you thaw fruit depends on how you plan to use it. For example:
- Unthawed: Fruits may generally be used straight from the freezer for baked goods such as blueberry crisp, raspberry pie, peach pie or for frozen desserts such as cherry or strawberry ice cream. If the fruits are frozen into one solid block, try partially thawing the fruit just to the point where the individual pieces can be separated from one another.
- Partially thawed: Fruits that will be used raw (uncooked) in a fruit cup, fruit salad or shortcake will hold their shape and texture better if they are only partially thawed.
- Completely thawed: Fruits that will be pureed or reduced to make sauces such as raspberry sauce to serve with cheesecake or blackberry sauce to serve with grilled duck or game should be completely thawed before they are processed.
Are there any drawbacks to freezing fruits?
- Softened Texture: While frozen fruits generally retain their flavor after freezing, the texture may be softer than it is for fresh fruit. That’s because most fruits are largely made up of water held within the cell walls that define the fruit’s structure and texture. If fruits are slowly frozen, large ice crystals form within the fruit’s cells, causing them to rupture. However, rapidly freezing fruits produces a large number of small ice crystals within the cell walls. The small crystals do less damage to the cells.
- Browning: As discussed above, some fruits, particularly tree fruits, can turn brown when sliced and must be treated with an anti-browning agent such as lemon juice or ascorbic acid (vitamin C) before they are frozen.
- Limited Freezer storage: If storage space is limited, don’t cram your freezer with more fruit than it can accommodate. As a general rule of thumb, this equates to about 2 to 3 pounds of fruit per cubic foot of freezer capacity. Allow space for air circulation between frozen food containers and keep the storage temperature at 0° F or lower.
In Conclusion
Freezing is one of the fastest, easiest, most convenient ways to preserve fruits. Although most fruits freeze quite well, results may vary depending on the quality of the fruit, how ripe it is, and how it is packed for freezing. To learn more about freezing fruit, check out the publications listed under Sources below. They provide additional details on specific fruits and the recommended freezing and packing methods for each.
FEATURED PHOTO: Pat Chadwick
SOURCES
The Fruit Gardener’s Bible (Hill, Lewis and Perry, Leonard, 2011)
Brief Instructions for Freezing Fruit, North Carolina State Extension Publication
Freezing Fruits, National Center for Home Food Preservation, University of Georgia
Freezing Fruits, North Dakota State University Extension Publication
Freezing Fruits and Vegetables, Clemson University Extension Factsheet HGIC 3063
Freezing Fruits, Step-by-Step, Clemson University Extension Factsheet HGIC 3067
Food Preservation: Freezing Fruits, Ohio State University Extension Publication
Freezing Fruits and Vegetables, Virginia Cooperative Extension Publication 348-596
